The effect of κ-distributed trapped electrons on fully nonlinear electrostatic solitary waves in an electron–positron-relativistic ion plasma

Abstract Based on the hydrodynamic model, the existence and propagation features of fully nonlinear electrostatic solitary waves in an unmagnetized, collisionless, homogenous three-component plasma have been investigated. The plasma containing cold relativistic ions, Boltzmann positrons, and trapped electrons modelled by κ -trapped distribution function. Employing the pseudo-potential method, the Sagdeev pseudo-potential and the first integral energy equation for the system as a function of the electrostatic potential (disturbance) have been derived. The influence of the relevant plasma configurations including the propagation pulse velocity, the superthermality index, the characteristic trapping parameter, the relativistic strength parameter, the positron density ratio, and the positron temperature ratio, on the properties of electrostatic solitary pulse profile has been determined. The results of our study may be helpful in better interpretation of the existence of localized structures in astrophysical and space plasmas as well as in laboratory plasmas, where the positron-ion plasmas with nonthermal trapped electrons can exist.